Association in solution and adsorption at an air-water interface of alternating copolymers of maleic anhydride and styrene
Association in solution and adsorption at an air-water interface of alternating copolymers of maleic anhydride and styrene
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DOI：
10.1021/la991440a
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发表时间：
2000-04-18
期刊：
影响因子：
3.9
通讯作者：
Revol, JF
中科院分区：
文献类型：
--
作者：
Garnier, G;Duskova-Smrckova, M;Revol, JF
用静态和动态光散射、表面张力和透射电子显微镜研究了交替聚(苯乙烯-马来酸酐)(SMA)在水溶液和空气-水界面上的行为。感兴趣的变量是聚合物浓度、相对分子质量和电离度随pH变化。SMA聚合物可以在水溶液中缔合。SMA在溶液中的临界尺寸范围从预测的高斯回转半径(r(G))到150 nm。分子量越小，缔合体的尺寸越大。在pH=6.5时测得缔合尺寸的最大值，这相当于聚合物盐以单钠形式存在。提出了一种SMA分子拉链形成由两个分子组成的横截面大线圈的机理。SMA分子也吸附在空气-水界面，很可能是以2D-螺旋的形式。平衡将SMA在溶液中和空气-水界面的浓度联系在一起。
The behavior of alternating poly(styrene-maleic anhydride) (SMA) in aqueous solution and at the air-water interface was studied by static and dynamic light scattering, by surface tension measurements, and by transmission electron microscopy (TEM). The variables of interest were the polymer concentration, the molecular weight, and the degree of ionization varied with pH. SMA polymers can associate in aqueous solution. The critical size of SMA in solution ranges from the predicted Gaussian radius of gyration (r(g)) up to 150 nm. The size of the associates increases with decreasing molecular weight. A maximum in associate size was measured at pH = 6.5, which corresponds to the polymer salt under its monosodium form. A mechanism by which SMA molecules zip together forming a macrocoil made of two molecules in cross section was proposed. SMA molecules also adsorb at the air-water interface, very likely as 2D-coils. An equilibrium links the concentration of SMA in solution and at the air-water interface.